1. Field of the Invention
The present invention relates to electric motor rotor technology and more particularly, to an improved design of electric motor rotor in which one core member is selectively used with two different magnetic units to constitute two different modes.
2. Description of the Related Art
Taiwan Utility model M345421 discloses an electric motor rotor, which comprises a cylindrical core member, a plurality of magnets bonded to and spaced around the periphery of the core member to form multiple magnetic zones, and a hoop attached to the magnets to secure the magnets to the core member positively and to prohibit falling of the magnets from the core member during rotation of the rotor in a stator. However, when bonding the magnets to the core member, alignment of the magnets is difficult to achieve. Thus, assembling the rotor takes much time. Further, if the magnets are not accurately bonded to the core member in position, the magnetic zones of the rotor will not be accurately aligned, affecting rotor performance.
To eliminate the aforesaid problem, the cited invention discloses another rotor design, which comprises a cylindrical core member having a plurality of mounting grooves equiangular spaced around the periphery thereof, a plurality of H-shaped locating members respectively affixed to the mounting grooves, and a plurality of magnets respectively mounted in between each two adjacent H-shaped locating members. Thus, the magnets can easily be set in a respective predetermined position without any alignment procedure. Further, the H-shaped locating members provide a function to secure the magnets in position. Therefore, no further hoop means is necessary to secure the magnets in position. Arranging the H-shaped locating members facilitates quick installation of the magnets and accurate positioning of the magnetic zones, however the arrangement of the H-shaped locating members relatively increases the rotor cost. Therefore, an improvement in this regard is necessary.